From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757868AbYFPSp6 (ORCPT ); Mon, 16 Jun 2008 14:45:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753475AbYFPSpt (ORCPT ); Mon, 16 Jun 2008 14:45:49 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39843 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753734AbYFPSps (ORCPT ); Mon, 16 Jun 2008 14:45:48 -0400 Message-ID: <4856AE64.7020906@zytor.com> Date: Mon, 16 Jun 2008 11:18:12 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Paul Jackson CC: Yinghai Lu , ying.huang@intel.com, mingo@elte.hu, tglx@linutronix.de, steiner@sgi.com, travis@sgi.com, linux-kernel@vger.kernel.org, andi@firstfloor.org, akpm@linux-foundation.org Subject: Re: [PATCH 4/8] x86 boot: allow overlapping ebda and efi memmap memory ranges References: <20080616062945.14597.78009.sendpatchset@polaris-admin.engr.sgi.com> <20080616063001.14597.96170.sendpatchset@polaris-admin.engr.sgi.com> <1213600062.11185.13.camel@caritas-dev.intel.com> <20080616032457.718f4d87.pj@sgi.com> <1213606435.12968.14.camel@caritas-dev.intel.com> <48568B56.7060307@zytor.com> <20080616113806.2ff4c1a4.pj@sgi.com> <48569D62.9050107@zytor.com> <20080616123721.bb9195e6.pj@sgi.com> <86802c440806161041v5f582d4y2a65adf57451a6d9@mail.gmail.com> <20080616130938.527283f7.pj@sgi.com> In-Reply-To: <20080616130938.527283f7.pj@sgi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul Jackson wrote: > Yinghai wrote: >> like to see to make reserve_ebda_region() more smart like the old >> way when andi introduced ebda_size... instead of reserve 0x9000 to >> 0x100000 all the way. > > Looking back at some older kernels, that code seems to have setup an > ebda region only if there was a non-zero real mode pointer at 0x40E. > > This is rather different than always setting up such a region. > Well, sort of. Only some very old systems will not have had one. 0x40E contains the pointer to the EBDA; this basically tests for the existence of an EBDA at all. -hpa